A transom is the vertical reinforcement which strengthens the stern of a boat.[1] This flat termination of the stern is typically above the waterline.[2]
The term was used as far back as Middle English in the 1300s, having come from Latin transversus (transverse) via Old French traversain (set crosswise).[1]
The stern of a boat is typically vertical. It can be raked such that there is an overhang above the water, as at the bow. A reverse transom is angled from the waterline forwards.[3]
Transoms can be used to support a rudder, outboard motor, or as a swimming and access platform.[4]
The Bermuda cedar transom of the Spirit of Bermuda
Flat transom on a dinghy with mount points for a rudder.
Raked transom with rudder mount points.
Reverse transom with rudder mounted under the hull.
Transom-mounted outboard motor.
Reverse transom with access platform.
Traditional timber construction with horizontal transom members in pale yellow-green (6) and turquoise (7).